1. Field of the Invention
The present invention relates to a differential signaling system which uses at least two signal wires to connect a driver circuit and a receiver circuit and transmits a small amplitude signal between at high rates of several hundred Mbps or higher. The invention also relates to a method of controlling the skew between the signal lines of such a differential signaling system, and to a connectorized cable and an information processing apparatus each of which is provided with such a differential signaling system.
2. Description of the Related Art
Due to high immunity to noise, especially to common mode noise, transmission of a differential signal by using two signal wires is commonly employed for transmitting a small amplitude signal at high rates of several hundred Mbps or higher.
However, differential signaling poses a problem that raising the transmission rate increases the effect of the propagation delay difference (skew) between the two signal lines. For example, a twisted pair cable as shown in FIG. 2 may have skew of 10 ps/m or more. If the transmission rate is 10 Gbps and the length is 5 m, signal reception is difficult at the receiver circuit since one signal shifts from the other signal by half of the time period of the signal.
In JP-A-2002-374312 (Patent Document 1), a variable delay circuit is provided on the input of the differential amplifier of the receiver circuit in order to solve the above-mentioned problem.